This proposal plans to explore the inter-relationships between growth, gonadarche and adrenarche during puberty. To this end, two patient populations will be studied: 1) subjects with central precocious puberty, and 2) patients with monotropic growth hormone deficiency undergoing puberty at a normal age. These groups have been selected since they would profit from a delay of their pubertal process. Each group will be examined intensively to determine the hormonal and clinical characteristics of their condition prior to and following administration of a long-acting analogue of the gonadotropin releasing hormone. This agonist, D-Trp6-Pro9-NET-LHRH (LHRHa), has been previously demonstrated to produce a selective chemical desensitization of pituitary gonadotropin release and now permits the study of the effects of selective withdrawal of gonadarche from the pubertal process for the first time. Thus the inter-relationships of gonadarche and adrenarche can be explored in a controlled manner and studied in a longitudinal fashion. In addition when the constraints of epiphyseal closure attendant upon the appearance of sex steroids is removed, considerable new information regarding growth in puberty will be forthcoming. This line of investigation should provide basic information regarding the relationships of several aspects of the pubertal process, have implications for both human and animal science, and potentially translate to therapies of several human disorders.